Trailer vehicles (“trailers”) now have diverse operating functions that are controlled by means of operating devices. The functions to be controlled may be, among many others, an electronic brake system (EBS), trailer central electronics (TCE) or the electronically controlled air suspension system (ECAS). Within the scope of these operating functions, numerous respective control functions are executed.
Heretofore, various individual elements such as switches, lamps, bistable flip-flop elements and simple displays have been used to present and control different operating functions. The many different elements can lead to high costs, since a separate housing as well as lines and plug connectors must be supplied for each element.
It frequently happens that a single, specific control function is assigned to a switch, for example. Conventionally, to ensure that the operating devices can be clearly understood and, thus, used easily for operator control, they are limited to specific operating or control functions. Thus, the conventional operating devices can be adapted to only a limited extent to altered control tasks. In addition, increased complexity is intentionally avoided with conventional operating devices, so that persons without prior knowledge can be introduced to operator control more easily. Nevertheless, conventional operating devices offer little intuitively learnable operating capability. Training sessions are typically required in order to impart understanding of the function of the operating elements (e.g., pushbuttons, etc.) arranged on the operating device, and they must be repeated regularly in the case of changes in the control electronics or of differently equipped trailers.
In addition to the control of operating functions, certain functions and operating parameters of trailers must be monitored in order to offer increased driving comfort and/or increased safety. Examples include monitoring of tire pressures, of mileage or of brake-lining wear. If defects or deviations are detected, they typically cause an indicator lamp to go on, and any error may be permanently stored in the control electronics for diagnostic purposes. Operating data of the operating parameters to be monitored are presented on separate display devices that are physically separate from the operating devices used for control.